In a vehicle such as an automobile, restraining protective seats for infants have been used in order to retain the sitting posture of an infant during travel and protect the infant from shock at the time of acceleration and deceleration. An infant restraining and protective seat of this kind is placed on a seat of the vehicle and is secured by a seat belt with which the vehicle seat is provided.
Among these infant restraining and protective seats, one of a reclining type has been developed in order to place an infant in a sleeping posture which will induce restful sleep when the infant is to sleep or in order to place the infant in a comfortable posture when the infant is relaxing.
FIG. 10 illustrates an example of such a common infant restraining protective seat capable of reclining. As is evident from FIG. 10, a restraining protective seat 1 for infants comprises a seat main unit 2 for seating an infant and a base 3 for supporting the infant in a reclinable manner. The mutually opposing surfaces of the seat main unit 2 and base 3 are curved surfaces that are arcuate in shape. The seat main unit 2 is adapted so as to be reclinable relative to the base 3 along these curved surfaces. A locking mechanism, not shown, which prevents relative movement between the seat main unit 2 and base 3 is controlled by an operating lever 4 to be placed in a locked state or an unlocked state, whereby the seat main unit 2 can be reclined to assume several reclining angles.
The main seat unit 2 is provided with an infant seat belt 5 comprising belts 5a for restraining the infant and a protective pad 5b. In this case, the seat main unit 2 is provided, at several locations in the vertical direction, with holes 2a through which the infant seat belt 5 is passed. This makes it possible to adjust the height of the infant seat belt 5 over several stages in conformity with the size of the infant.
As shown in the same Figure, the infant restraining protective seat 1 thus constructed has its base 3 placed upon a vehicle seat 6, and a seat belt 7 with which the vehicle seat 6 is provided it tightened upon being passed through a mounting hole 8 or a mounting hole 9 formed in the seat main unit 2, thereby fixing the restraining protective seat 1 to the vehicle seat 6.
However, in such an arrangement in which the seat belt 7 is passed through the mounting hole 8 of the seat main unit 2 and then tightened, the seat belt 7 and a seat belt setting portion 2b of the seat main unit 2 are firmly engaged. Consequently, when it is attempted to recline the seat main unit 2 from the presently set reclining angle to another angle, reclining cannot be achieved with the seat belt 7 in the tightened state. Accordingly, the seat belt 7 must first be released from the tightened state and then re-tightened after the seat main body 2 has been turned to the desired reclining angle. Thus, labor is involved in changing the reclining angle of the seat main unit 2. In particular, an infant presently awake often falls asleep and the reclining operation is particularly troublesome when it is attempted to change the reclining angle while the infant is still asleep.
One method of solving this problem is to tighten the base 3 by the seat belt 7, rather than tightening the seat main unit 2 by the seat belt 7 directly. With such an arrangement, however, the infant restraining protective seat 1 is subjected to a large inertial force when the vehicle undergoes deceleration in excess of a predetermined value. As a result, the seat main unit 2 slides with respect to the base 3 and a change is produced in the reclining attitude of the infant restraining protective seat 1. In order to prevent such a change in reclining attitude at the time of great deceleration, a strength maintaining mechanism is required between the seat main unit 2 and the base 3. However, not only must this strength maintaining mechanism be large in size in order to resist such a large force, but the mechanism is inevitably complicated in structure so as not to detract from the reclining function. Accordingly, the infant restraining protective seat 1 is heavy and troublesome to handle.
The present invention has been devised in view of these problems and its object is to provide a restraining protective seat for infants in which the reclining angle can be changed in simple fashion while the seat belt is maintained in a tightened state.
Another object of the present invention is to provide a restraining protective seat for infants in which the reclining attitude can be held with assurance, even at the time of great deceleration, without requiring a complicated force maintaining mechanism, the seat being light in weight and easy to handle.